Right ventricular longitudinal function is associated with exercise capacity in pre-capillary pulmonary hypertension: a multimodality imaging study.

AIMS: Right ventricular (RV) failure is a key determinant of outcome in precapillary pulmonary hypertension (PHprecap). Contemporary four-strata risk assessment incorporates functional capacity and NT-proBNP, yet the relationship between these and RV function remains unclear. We therefore examined these associations in PHprecap.

METHODS AND

RESULTS

Patients with PHprecap [n = 49; 69% women, median age 62 (IQR 52,74) years] underwent 6-min walk distance (6MWD), NT-proBNP sampling, right heart catheterization, and comprehensive RV assessment by echocardiography and cardiac magnetic resonance imaging (CMR) most within 24 h. RV function was impaired (RVEFCMR 41%, FWSECHO 15%, and FACECHO 30%), 6MWD was reduced (315 m), and NT-proBNP was elevated (1078 ng/L). In multivariable analysis adjusted for age and sex, 6MWD was associated with RV longitudinal function parameters (adjusted R 2 = 0.33-0.50, all P < 0.05), including FWS (B = -15.2, 95% CI -22.3 to -8; P < 0.001) and TAPSE/sPAP (B = 338.6, 95% CI 179.7-498.7; P < 0.001). In univariable analysis, log10(NT-proBNP) was associated with TAPSE, RV-PA coupling parameters, AVPD, and CMR-derived FWS (all P < 0.05), but only TAPSE/sPAP, S'/sPAP, and CMR-FWS remained significant after adjustment for mean right atrial pressure. Combined models showed minimal incremental explanatory value of RV function for 6MWD, whereas AVPD and age were the only independent predictors (adjusted R 2 ≈ 0.50).

CONCLUSION

Impaired RV longitudinal function is significantly associated with exercise capacity independent of imaging modality and confounders, whereas NT-proBNP provides a moderate reflection of right-sided filling pressures. Resting RV assessment may underestimate disease severity, and stress-based evaluation could better capture functional impairment in PHprecap.